While working on Just Let Me Go, I found myself in the need of making floaty hair for a ghost-like character in the game. The idea was to make a hair that looked like my character was underwater, so I began to experiment with different ways to do it. You can see the final result in the video below.
It took me a while to experiment, but after testing a wide variety of things I found a good way to get the result I wanted. First, I decided I wanted a force that would push the hair upwards, basically countering the gravity, but without actually turning off gravity. I found turning off gravity didn’t give me the result I wanted because the hair already had a default shape, and that caused some issues.
What I did was add some air force in the External Forces field, to push the hair upwards. You can try different forces, depending on the length of your hair and scale of your model. In my case I found this worked pretty well.
Another thing I did was modify the Collision Constraints, more specifically, the Strands Viscosity. I found that using a vey low viscosity made the hair lose some weight, and that caused the hair to look somewhat floaty, which is what I needed.
Another interesting parameter is the Strands Size in the Strands Parameters roll-down. From what I understand, this defines how many control points the hair has. The more control points, the better the deformation will be. So, if you use very few, the hair will look more “stiff.”
Lastly, I modified the Bend Constraint parameters to tweak how the hair bends. My idea was for the hair to have very little resistance to bending, so it could produce a lot of nice curls while the ghost is flying around.
Keep in mind these are not the only settings that will reproduce this effect. You can experiment with different values until you find what fits your needs. However, I figured this could be a nice start.